The present invention relates to an apertured film material useful as a body side liner of an absorbent article. The film material has an additive combination applied to its surface. The additive combination provides improved fluid transfer across the cover, and it is capable of reducing frictional forces during processing of the absorbent article.
There are several types of covers that have been or are currently in use for tampons: woven fabrics, nonwoven fabrics, apertured films, reticulated films, polymer nets, and the like. While the patent literature has suggested that a progression from nonwoven fabrics to apertured films in these covers is desired, this has not yet occurred commercially. In order to commercialize this desirable tampon, several issues must be overcome. First, apertured films are generally hydrophobic in nature, and this can reduce the ease with which bodily fluids can be accepted into the absorbent structure enclosed within the covers. Second, apertured films have significantly different friction characteristics than nonwoven fabrics. This can create processing difficulties, especially in tampon presses in which compressed tampons are subjected to axial ejection forces, such as disclosed in U.S. Pat. Nos. 3,343,225 (Hochstrasser et al.), 3,348,866 (Etz), 3,422,496 (Wolff et al.), 3,477,102 (Etz) 3,515,138 (Hochstrasser et al.), 3,688,346 (Johst et al.), 3,852,847 (Etz), 4,081,884 (Johst et al.), 4,498,218 (Friese), and 4,453,296 (Friese), European Pat. App. No. 0 623 333 (Karl Ruggli AG), European Pat. App. No. 0 639 363 (Karl Ruggli AG), and European Pat. No. 0 422 660 (Johnson and Johnson GmbH).
Nonwoven fabric covers may be incorporated into tampons as described in Friese, U.S. Pat. Nos. 4,816,100; 4,836,450; and 4,859,273. These tampons can then be made into tampons as described in the patents identified above.
Apertured film covers have been incorporated into sanitary napkins to increase the products"" ability to hide absorbed bodily fluids. An example of such an apertured film cover is disclosed in McNeil-PPC, Inc., EP 0 900 071. This advancement relates to the corona treatment of an apertured film for application thereon of a water-borne surfactant. This significant advance in the art, nonetheless requires numerous processing steps, and there sanitary napkins produced therefrom are not subjected to the high axial friction seen in the tampon manufacturing processes described above.
Therefore, what is needed is an apertured film material useful as a body-side liner or cover of an absorbent article, such as a tampon, that is processable in a commercially efficient manner, that provides satisfactory fluid transport into the absorbent article, and that aids in removal of the tampon from an overwrapper or applicator prior to and/or during use.
The present invention relates to a polymeric film material useful as a body-side liner of an absorbent article. The film material comprises an apertured polymeric film web and an additive combination applied thereto. The additive combination is formed of about 10 to about 90 wt-% of the hydrophilic agent and about 90 to about 10 wt-% of the lyophilic agent. The film material exhibits a sinking basket test time of less than about 25 seconds.
The present invention also relates to a catamenial tampon comprising an absorbent structure, a withdrawal string, and the polymeric film material described above substantially enclosing the absorbent structure.
The invention further relates to a process for the manufacture of a tampon. The process includes
a) applying up to about 1 gsm of an additive composition to a web of fluid-impervious plastic material formed into an apertured film material
b) separating an individual sheet from the web;
c) attaching the individual sheet to an absorbent sliver;
d) forming the absorbent sliver into a tampon blank;
e) compressing the tampon blank in a press; and
f) applying an ejection force to the compressed tampon in an axial direction to eject the tampon from the press.
In the above process, the additive combination comprises 10 to about 90 wt-% of the hydrophilic agent and about 90 to about 10 wt-% of the lyophilic agent, and the film material provides a sinking basket test time of less than about 25 seconds. Further, when the tampon blank is formed, the individual sheet substantially encloses it. The compressed tampon is substantially cylindrical, and it has an outer cover comprising the individual sheet.